Answer:
I am nothing but holes tied to holes, yet am strong as iron.
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
Neither bought nor sold but more valuable than gold. It is built but not by hand. What is it?
Goes over all the hills and hollows. Bites hard, but never swallows.
What get wet while drying
How can you tell when a mummy has a cold?